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I was just in my r75/6 a couple of weeks ago and the only screws are on the oil pump housing. Everything else is a bolt, be it on the clutch or the flywheel. So I'm not sure where these screws are.

I think the '70 R75/5 must be a holdover from the /2s. My '69 R69S has countersunk flathead screws. You're /6 has bolts. My /7 has allen head bolts. Being one of the first models after the /2s, seems likely that he would have screws.

And a small point...maybe I remembered this wrong... A bolt is a fastener that is held in place by a nut on the other end. A screw is a fastener that is held in place by its own threads. Are we talking about screws in this situation, just different heads?

bolt - An externally threaded, cylindrical fastener with a head at one end and a threaded blunt end at the other. Bolts are designed to fit into non-threaded holes to join parts and are assembled with a nut.

screw - An externally threaded, cylindrical fastener with a head and a threaded flat or pointed end opposite the head. Screws are designed either to fit into a threaded hole or form threads into material.

To clarify, the "screw" is part #21 21 1 231 463 Filister Head Screw. I put PB Blaster on them last night and will wait until this weekend when the garage should be a little warmer. I'll try the impact again and a large flat screwdriver. I'm not sure that I can put enough pressure against the screwdriver to break them loose however.

Thanks for the input. Glad to know that I'm not going to ruin things with PB Blaster. I can always clean all after it is apart.

Realize that the threads of the screw and what they're screwed into are not near the rear face of the clutch pack...the thing you see on the back is the compression ring. The screws thread into a raised edge of the flywheel. If that is where these screws are sticking, that is where you need to get the penetrant. Can you get behind the compression ring to get penetrant on the actual threads?

I can't imagine getting "behind" these screws with any penetrating oil. I'm trying to get PB blaster around the face of the screw. I'll put some more on today and probably try again with the impact this weekend.

OK- after further review- I think there IS a way to spray a little PB Blast behind the screws. It appears there is a spacer and if the flywheel is rotated, I was able to bend the straw and spray some behind the screw. I tried impact on all screws and none moved. If the engine is turned, you can access the bottom of the clutch and try each screw which seems the easiest access. I have sprayed again heavily (turning the garage into a hazmat site)and will try again tomorrow. I'll find the heat gun in the meantime.

Tried paint stripper gun today. No luck. I held the gun up for about 3-4 minutes on one screw. Heat gun temp is supposed to be 700-800. Not sure if I tried enough time or temp. Tried to light my cheap propane torch and couldn't get it to light.

Found ADDITIONAL way to access behind with solvent by rotating to point screw is visible in timing window. Sprayed more PB Blaster through the window onto the back of the screw/spacer.

So have I heated it enough? Does anyone know if there is a larger flat blade bit available? It seems like the standard bit that seems to come with all of the kits is about a half of the size to properly fit in the slot. That is, I'm leaving about half a slot surface area unused when trying to impact. Maybe there is a special tool? Seems like the flywheel could be blocked somehow and a breaker bar/large flat blade screwdriver combination?

It seems like the standard bit that seems to come with all of the kits is about a half of the size to properly fit in the slot. That is, I'm leaving about half a slot surface area unused when trying to impact. Maybe there is a special tool? Seems like the flywheel could be blocked somehow and a breaker bar/large flat blade screwdriver combination?

You need to find a tool that is thick enough to fill the slot, and wide enough to fit the length of the slot. It would be nice if it had a hex that would fit the impact driver. If not, it would be nice if it had a hex that would fit an impact socket that would fit an impact driver. You need to measure the slots in those capscrews and go to a good tool store or get on line and find something that fits.

Then, either fix or replace the torch. One of the small (one-hand size) butane torches would be perfect for these capscrews. Then apply the heat directly to the head of the screw. I don't think my heat gun would be sufficient for this application.

The biggest bit here might work. I'm not sure because I haven't seen the screw head like that in 25 years, if then.

For All of you Mechanic's and Self doer‘«÷s out there. Penetrating Oil - interesting.

This was in one of the Military Vehicle Club newsletters:
Recently ‘«£Machinist Workshop Magazine‘«ō did a test on penetrating oils. Using nuts and bolts that they ‘«ˇscientifically rusted‘«÷ to a uniform degree by soaking in salt water, they then tested the break-out torque required to loosen the nuts. They treated the nuts with a variety of penetrants and measured the torque required to loosen them.
This is what they came up with:
Nothing: 516 lbs
WD-40: 238 lbs;
PB Blaster: 214 lbs;
Liquid Wrench: 127 lbs,
Kano Kroil: 106 lbs
(ATF)/Acetone mix (50/50): 50 lbs.

This last ‘«£shop brew‘«ō of 50% automatic transmission fluid and 50% acetone appears to beat out the commercially prepared products costing far more.

Thanks Paul. I looked at the sites. The slot is approx 1/2" wide and the largest bit in the kit that I bought (for less than $10.00 and looks exactly like the complete kit in the photos for $30) is approx 3/8".

The bits shown do not list sizes, so I'm not sure if the largest one is any larger than what I have, but I may gamble and buy a set to find out.

In the meantime, i'm going to keep spraying solvent and put some more heat on it.

I'm aftaid to heat too much and warp or crack. Should this even be a worry?

I'm aftaid to heat too much and warp or crack. Should this even be a worry?

if you're using a heat gun.. no worries.

i have a Milwaukee paint stripping gun, and regularly use it for heating up pivot bearings on my oilhead. that loctite requires about 270 degs. before it lets go. i don't use a IR temp sensor, but i've found that about 2 songs on the radio is the right amount of time to leave it on there.

You really are NOT gonna apply enough heat with a heat gun to hurt anything, nor really to get the threads to the temperature necessary to break them loose with impact. YOU NEED A TORCH....It really is that simple. You put the tip of the flame on the head of the screw, keep heating it until a gob of spit on your finger applied to the head will sizzle.....Crude but effective..........

Go to any good auto supply outfit and request a screwdrive tip to meet your needs. They are typically sold in a set; but it is common to get one up to perhaps an 1/8 inch thick blade. Really, what you are doing is daunting task that requires the right technique; but observe what others are actually advising you......FOLLOW THE WRITTEN ADVICE and techniques that others KNOW works......Good luck and God bless..........Dennis